The present invention relates generally to a process and apparatus for the desalinization of sea water and, more particularly, to such a process and apparatus which is simple and can produce large quantities of usable desalinated water at low cost.
The term "sea water" as used herein is intended to refer to ocean water, and the like, having a sufficiently high total dissolved solid content so that the water is unusable for agricultural purposes. The term "desalinated water" used herein is intended to refer to water in which the total dissolved solids are reduced to a level sufficient to render the water at least suitable for irrigation purposes.
U.S. Pat. No. 4,122,012, the disclosure of which is incorporated herein by reference, discloses a sea water desalinization system which includes a barrier buried to a depth below the low tide water level in a sandy beach, and a collector vault or well buried in the beach behind the barrier, the vault having an opening in its side for receiving water passing through the barrier. The barrier is filled with selected filter materials and the sand in the area between the barrier and the well is treated with a selected material, such as the sap of the guayule plant. After a period of pumping, it is stated that desalinated water will appear in the well and may be pumped out of it.
While the system of U.S. Pat. No. 4,122,012 may produce some desalinated water, it cannot as a practical matter produce such water in significant or large quantities because the sand in most areas is not sufficiently porous or water-permeable to allow an adequate flow therethrough of water to the barrier and to the well. It is stated in this patent that, should the sand be very small and dense to retard water flow, it may be replaced with small size gravel to increase the water flow. The replacement of the sand with gravel, however, is both time-consuming and expensive.
A need has arisen, therefore for such a water desalinization system which can utilize the existing materials in the beach without requiring the removal or replacement of same. The process and apparatus of the present invention fills this need.